A bibliographic review (150 references) on potentiometric stripping analysis (PSA) is performed. Theoretical, instrumental, analytical applications and advantages, and inferences of other modern PSA techniques are considered, like derivative PSA, constant-current PSA, multichannel potentiometric monitoring stripping analysis, differential PSA, constant-current enhanced PSA, derivative adsorptive PSA, kinetic PSA and reductive PSA. Implementation of PSA in flow systems is also considered, namely continuous-flow and flow-injection systems.

Potentiometric Stripping Analysis: A Review

Based on high-pressure ashing, the potential to determine some trace metals (Zn, Cd, Pb, Cu, Ni, Co, Al, Tl, Cr, Fe) by anodic or cathodic stripping voltammetry in the square wave (SWV) and differential pulse modes (DPASV) is described. In comparison to the differential pulse mode, the square wave mode shows advantages for cathodic stripping and for zinc determination.

Present potential of electrochemical methods for metal determinations in reference materials

The direct determination of traces of certain heavy metals in oils is possible after treatment of the methanolic sample solution with Lumatom (tetramethylammoniumhydroxide). For the inverse voltammetric determination, a flow through cell with a mercury film electrode is used. The results for the determination of Cu and Pb in some edible oils after solubilization agree well with those obtained using wet oxidative high pressure ashing.

Direct inverse voltammetric determination of Pb, Cu and Cd in some edible oils after solubilization

A computerized system for potentiometric stripping analysis made of commercially available components with corresponding software is described. Application to the determination of lead in wines and vinegars is also reported.

Computerized potentiometric stripping analysis using asyst software: Application to lead determination in wines and vinegars†

The conditions for the inverse-voltammetric determination of cadmium, lead, and copper in various biological samples after solubilization with Texapon are described. The results of this procedure are compared with those obtained with conventional high- and low-pressure wet digestions. The advantages of the Hg-film electrode as compared to the stationary Hg-electrode are discussed.

Inverse-voltammetric determination of cadmium, lead and copper in animal samples after solubilization

The determination of lead and cadmium in biological materials was carried out by potentiometric stripping analysis. Supporting electrolyte was a mixture of NaCl and HCl. In the presence of 4% lumatom in methanol, oxidation potentials of −0.46 V for Pb and −0.68 V for Cd were found (vs. SCE). The method was applied to different standard reference materials (leaves, needles, hair) and was also compared with the differential pulse anodic stripping technique. The latter presented considerable difficulties, in particular by the interference of oxygen.

M. Rozali bin Othman

Papers

Determination of lead and cadmium in biological samples by potentiometric stripping analysis